Here's some stuff I like...
Jeffrey Lewis. My favorite "anti-folk" singer/songwriter. Really creative and quite prolific. He's also an excellent cartoonist.
Obo Martin. Brilliant psychedelic songwriter. Ever hear of The Be Good Tanyas? They took their name from one of his songs.
Dan Bern. Dan wrote the really good songs on the Walk Hard soundtrack. He's also got around 15 albums. The best tracks on them are among my favorite songs of all time.
Will Franken. The funniest man alive? Could be. Insanely prolific, really creative, not very p.c. Check out his podcast -- it's great.
Marc Wilson. Excellent writer and animator. He had a short video in Spike and Mike. Check out his bible blog.
David Dondero. Fantastic folk music singer/songwriter. His Songs have been stuck in my head for years.